[WORLD CUP QUALIFYING] Not much has gone right for the U.S. national team heading into its toughest two-match stretch of the Concacaf Hexagonal, after which it will have completed one-half of its schedule in this final qualifying round for the 2010 World Cup.

The first and second choices at right back, Steve Cherundolo (hip) and Frankie Hejduk (groin), respectively, as well as midfielder Maurice Edu (knee) are sidelined by injuries at least for the first game Wednesday (ESPN, Galavision, 10 p.m. ET) at Estadio Ricardo Saprissa in San Jose, Costa Rica. In the seven away World Cup qualifiers played in that country, the USA has lost six and tied one, and that one tie came in 1985.

Called into the squad as a late replacement is Houston midfielder Ricardo Clark, who is expected to arrive in Costa Rica on Tuesday. He joins seven U.S. teammates who were in the squad for the last visit to Saprissa, a 3-0 loss in 2005, though he and defender Danny Califf did not play. On the field that day were Tim Howard, Carlos Bocanegra, Oguchi Onyewu, Pablo Mastroeni, Brian Ching and DaMarcus Beasley.

Costa Rica is second in the group with six points with two wins and a loss, and can take over first place by winning, since the other four teams aren't in action until the weekend.

Training sessions on Monday and Tuesday were scheduled to help the players acclimate to the artificial surface laid down at Saprissa several years ago. By most accounts it is already showing signs of wear. The harsh surface, plus a tight turnaround between games four and five and the injuries and tough opposition, will present Coach Bob Bradley with perhaps his most daunting problems since taking the job 36 games ago.

"The game on artificial turf depends on a few things, one is the quality of that turf," says Bradley. "Is it old? Is it new? How hard is it? The second factor is, is the turf dry? Has it been wet down? Is it raining? These are all things that affect the speed of the game, the bounces, it affects how much give there is in terms of players, when they're cutting or going to the ground."

Marvell Wynne of Toronto FC is the only player on the U.S. roster who plays his home games on artificial turf (BMO Field). That experience may help his chances of seeing action Wednesday, though the primary candidate to play right back is West Ham defender Jonathan Spector, who missed most of the English season with injuries but has been healthy for the past few months. A longshot candidate is another English league veteran, Jay DeMerit of Watford.

"He has done very well to overcome some injuries and deal with some of the tough moments that have come his way," says Bradley. "He's a very good guy, as a person, one that makes the group better."

Three days after playing Costa Rica, the USA will face a Honduran team that began training in Florida a week ago to prepare for the match at Soldier Field in Chicago. To facilitate the U.S. participation in the Confederations Cup, for which it departs June 8 to South Africa, Concacaf moved the Costa Rica-USA game to Wednesday. The other five games in this double-date will be played Saturday and next Wednesday, which are the regular FIFA international fixture dates.

"We recognize that this is a unique double fixture date starting because the schedule was changed to take into account the Confederations Cup," says Bradley. "We understand the different challenges that go with this one. When we get back to Chicago, playing at home is important. This particular occasion, Honduras comes in rested. We'll need to look at everything and, as always, try to assess where we are physically, mentally and make the decisions at the appropriate time."

Honduras is also the last team to beat the USA on its home soil in a qualifier: a 3-2 win at RFK Stadium in September, 2001, that preceded by a few days a U.S. loss in Costa Rica.

Bradley has decisions to make at left back as well as whether to play Wynne or Spector on the right. He used Beasley in that role earlier this year, and has both Heath Pearce and Jonathan Bornstein available for these games.

The Costa Ricans, especially at home, will be tough to handle in the attack regardless of who runs up that side, and since Beasley played for the USA more than two months ago he managed only 15 minutes for Glasgow Rangers before suffering a rib injury that forced him out of a league match against St. Mirren. Pearce has ridden the bench the past five months for German club Hansa Rostock; Bornstein has been in regular league action for Chivas USA but has yet to play in the Hexagonal.

With a central defensive core of Onyewu and Bocanegra, with probably Michael Bradley and Mastroeni in front of those two, and Howard backing them up, the USA can perhaps hold the middle secure enough to minimize thrusts through the middle. But on the flanks is where it will be tested and must prevail at both ends of the field to secure a result.